The objective of the research is to advance means for the diagnosis, prevention and control of viral infections through systematic studies of the immunology, etiology, and epidemiology of human and animal infections. Professional staff of the California Department of Health, Viral and Rickettsial Disease Laboratory collaborate jointly with other medical and research facilities in multidisciplinary studies: 1. To detect and characterize previously unrecognized viruses. 2. To determine the etiologic role of viral agents, including those in latent, persistent, chronic or altered states of infectivity, in various acute and chronic syndromes of uncertain cause. 3. To identify and characterize various viral antigens and antibodies and their interactions, and to elucidate the processes of viral replication and virus host-cell interaction at the cellular, molecular and ultrastructural level. 4. To adapt findings from these studies to develop and evaluate new or improved laboratory diagnostic procedures for use in clinical virology. 5. To apply viral laboratory technology in joint laboratory/field investigations to elucidate the epidemiology and natural history of selected viral diseases, especially those due to arboviruses, vector-borne and zoonotic agents.